493e57c195
If the userdata starts with the text '## template:jinja', Jinja2 templating engine will be used to render that userdata. This feature leverages the get_instance_data metadata service implementation and tries to be as close as possible with the cloud-init's implementation. Change-Id: I79cb0066f7d65ae27867ac01b443e9be432b4dc3
51 lines
1.8 KiB
Python
51 lines
1.8 KiB
Python
# Copyright 2019 Cloudbase Solutions Srl
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import jinja2
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from cloudbaseinit.utils.template_engine import base_template
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from jinja2 import runtime
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MISSING_JINJA_VARIABLE = u'CI_MISSING_JINJA_VAR/'
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@runtime.implements_to_string
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class MissingJinjaVariable(jinja2.DebugUndefined):
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"""Missing Jinja2 variable class."""
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def __str__(self):
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return u'%s%s' % (MISSING_JINJA_VARIABLE, self._undefined_name)
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class Jinja2TemplateEngine(base_template.BaseTemplateEngine):
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def get_template_type(self):
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return 'jinja'
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def render(self, data, raw_template):
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"""Renders the template using Jinja2 template engine
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The data variable is a dict which contains the key-values
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that will be used to render the template.
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The template is an encoded string which can contain special
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constructions that will be used by the template engine.
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The return value will be an encoded string.
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"""
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template = self.remove_template_definition(raw_template).decode()
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jinja_template = jinja2.Template(template,
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trim_blocks=True,
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undefined=MissingJinjaVariable,)
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return jinja_template.render(**data).encode()
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